Page printer mechanism with tilting and travelling print head



Dec. 13, 1966 J. A BURCHFIELD ETAL 3,291,941

PAGE PRINTER MECHANISM WITH TILTING AND TRAVELLING PRINT HEAD Original Filed July 24, 1963 2 Sheet-Sheec 1 INVENTORS JAMES DLBUQQHFIELD, AAMES E.BELLNCTER, \F.

ZQ M H. MAQN'EILL.

BY W Z W ATTORNEY5 Dec. 13, 1966 I J. A. BURCHFIELD ETAL 3,

PAGE PRINTER MECHANISM WITH TILTING AND TRAVELLING PRINT HEAD Original Filed July 24, 1965 2 Sheets-Sheet 2 IZESET COUNTER 5915a ADDEIZ 3 l i i W INVENTORS JAMES A. BUZCHFELD, James E..BELLIMGEIZJ. o1-m H MAQNElLL ATTORNEY;

United States Patent 3,291,041 PAGE PRHNTER MECHANISM WETH TILTKNG AND TRAVELLENG PRINT HEAD James A. Eurchiield, Melbourne, James E. Bellinger, Jr., Eau Gailie, and John H. MacNeili, Indialantie, Fla, assignors to Sorohan Engineering, Inc, Melbourne, Fla, a corporation of Florida Continuation of application Ser. No. 297,419, July 24, 1963. This application July 2, 1965, fier. No. 469,260 9 Claims. (Cl. fill-93) This application is a continuation of US. application Serial No. 297,419, filed July 24, 1963, now abandoned, in the names of James A. Burchfield, James E. Bellinger, Jr. and John H. MacNeill and entitled Page Printer Mechanism.

The present invention relates to printing mechanisms and more particularly to a high-speed page or multipleline printing mechanism.

It is an object of the present invention to provide a high-speed page printing mechanism in which substan tially the only apparatus required to traverse across the page is the printing head or font itself.

It is another object of the present invention to provide a high-speed, page printing mechanism in which the page is held stationary during printing of a line and in which a type font on which the characters to be printed are arranged is traversed across the page While the mechanism for selecting the particular character on the font to be presented to the page during any printing cycle is stationary but is permanently coupled to the type font via light-weight gearing mechanisms.

It is another object of the present invention to provide a high speed printing mechanism in which a cylindrical, type font having characters arranged thereon in rows and columns is selectively stepped across a page on which printing is to be applied and in which the particular character to be printed at any given position is selected by translating mechanisms located at stationary positions on one or the other side of the printing apparatus, and in which the selection mechanism is coupled to the type font by suitable gearing, one portion of which is carried with the type font to permit character selection.

It is another object of the present invention to provide a high speed page printer in which characters to be printed are carried on a rotatable and translatable cylinder in the form of bands and columns on the cylinder and in which both rotation and translation of the font is accomplished by identical mechanisms, both of which provide only translatory motion and in which the translatory motion in one case is converted by appropriate gearing to a rotational motion, the gearing mechanisms employed also providing coupling between the movable type font which is incrementally stepped across a page during printing and the selection mechanisms which are at all times stationary.

It is another object of the present invention to provide a high speed printing mechanism in which a light-weight, cylindrical type font is stepped incrementally across a page to be printed and in which the more bulky and high inertia character selection mechanisms employed to position the font are stationary and in which gearing is provided between the stationary selection mechanisms and the font with only a small light-light proportion of the gearing required to he carried along with the font across the paper.

It is still another object of the present invention to provide a page printer in which, due to the fact that the selection mechanism is stationary and the type font is moved relative thereto, the position of the type font is shifted relative to the selection mechanism each time the type font is stepped one increment across the page and in which means are provided for altering the input code applied to the selection mechanism as a function of the 'ice position of the font relative to a specific location such as the leftmost column of the page.

It is yet another object of the present invention to provide a high speed page printing mechanism employing conventional platen and platen advance mechanisms, conventional ribbon feed mechanisms, etc. in which the characters to be printed are formed on a cylindrical font adapted to be stepped incrementally across the page while the character selection mechanism is stationary and in which the type font is nodded towards the platen so as to effect printing.

The above and still further objects, features and advantages of the present invention will become apparent upon consideration of the following detailed description of several specific embodiments thereof, especially when taken in conjunction with the accompanying drawings, wherein:

FIGURE 1 is a perspective view of the apparatus of the present invention;

FIGURE 2 is a sectional view through the type font carriage mechanism;

FIGURE 3 is a perspective view of the type font positioning and the gearing mechanisms for transmitting the movements of the character selection mechanisms directly to the type font;

FIGURE 4 is a schematic electrical block diagram illustrating the method for shifting the home position of the selection mechanism as the font is stepped across the p FIGURE 5 is a partial cross-sectional view of a modification of the apparatus of FIGURE 2 which modification concerns the method of the apparatus employed to effect the printing operation.

Referring now specifically to FIGURE 1 of the accompanying drawings, there is illustrated a perspective view of the high speed page printing mechanism of the present invention. The mechanism is provided with a translatable type-font carriage 1, employed to transport a type font 2. The type font 2 may be selectively rotated and translated to select for printing a particular character embossed on the font. The type font 2 in the specific embodiment illustrated has 64 characters formed thereon,- the number of characters being a function of the specific system in which the apparatus is to be employed. The characters in the illustrated font design are arranged in eight rows parallel to its longitudinal axis and eight circurnferential bands with each character formed on a distinct flat on the font.

The printing mechanism is provided with a platen 3, and with paper guide and feed arrangements all of which are wholly conventional in the typewriter art. An inked ribbon 4, extends across the entire Width of the machine and is disposed between the type font carrier 2 and the platen 3, being perpendicular to a radius of the platen 3 at the point of impact between the font 2 and the platen 3 during a printing operation. Printing is accomplished by causing the type font 2 to be moved into engagement with the platen 3 by suitable means, at least two of which are described herein.

The interior of the type font 2, is hollow and internally splined so that it may be translated longitudinally along a splined shaft 6. The font 2, is adapted to be moved along the spline-d shaft 6, so as to present any one of its 8 bands to the printing region adjacent the ribbon 4. The splined shaft 6 is carried by a rotatable shaft 7 having its longitudinal axis extending perpendicular to the axis of the splined shaft 6. The shaft 7 lies parallel to the direction of travel of the type front 2 and is rotatably supported in end walls 5 and it of the type front carrier 1 for purposesv to be described subsequently. The circumferential surface of the shaft 6 is smooth where it passes through the shaft 7, so as to provide a smooth continuous bearing surface since the shaft 6 must rotate within the shaft 7 to select one of its 8 columns for presentation to the platen 3. The shaft 7 is rotatably mounted to permit the font 2 to be nodded into engagement with platen 3.

The lower end of the shaft 6 has a plastic thimble which bottoms on a horizontal surface of a lower carrier guide rail 8 and secured to the shaft 6, immediately above the lower guide rail 8, is a pinion 9 which mates with a rack gear 11. The rack 11 is adapted to be translated perpendicular to the plane of FIGURE 2, so as to rotate the shaft 6, in order to present a specific column of the type font 2 to the paper on the platen 3.

A pair of rack gears 12 and 13, see FIGURE 3, are disposed on opposite sides of the type font 2, parallel thereto. A lower cross member 14, and an upper cross member 16, extend between the rack gears 12 and 13, so as to provide an open foursided frame work. C-ross members 14 and 16 are apertured to receive splined shaft 6, the members 14 and 16 providing bearing surfaces for the shaft so that it may rotate relative thereto and the members 14 and 16 may be translated along the shaft. The rack gears 12 and 13 are engaged by sector gears 17 and 18, respectively, carried on a splined shaft 19. The gears 17 and 18 are actually mounted on a collar 21, the collar being internally splined so that it may traverse with the carrier 1 while maintaining its position relative to the shaft 19. The sector gears 17 and 18 are rotated to produce translation of the [frame member comprising racks 12 and 13 and cross pieces 14 and 16. The type font 2, is positioned between the cross members 14 and 16, and therefore, upon translation of these cross members, the type font is caused to translate along the shaft 6 so as to select the specific band of characters to be aligned with the print position of the apparatus relative to the platen 3 and the ribbon 4.

The type font carrier 1, is provided with a bottom horizontal surface 22, which engages an upper horizontal surface 23, of the lower carrier guide rail 8. The type font carrier 1, is also provided with a downwardly extending projection 24, providing a vertical surface 26, which engages a vertical surface 27 of the lower guide rail 8. The apparatus is provided with an upper guide rail 28, providing a horizontal surface 29, which is engaged by outwardly extending horizontal surface 31 provided on the carrier 1. The lower and upper guide rails 8 and 28, respectively, extend across the entire width of the mechanism between a left side frame member 32 and a right side member 33, so that the carrier 1, is guided throughout its entire travel across the mechanism.

As viewed in FIGURES 1 and 2, the type font carrier 1, is provided with a top member 30 having a vertical aperture 35, through which passes the upper end of the shaft 6. The shaft 6 is provided with a bushing 34, in this region, and the bushing is captured by the inner surfaces of two side legs of a U-shaped channel member 36. The member 36 extends across the width of the mechanism substantially between the side frame members 32 and 33. Each end of the U-shaped channel member 36 is supported on a pivot arm, the right pivot arm 37, as viewed in FIGURE 1, being the only arm illustrated. The pivot arm 37, is pivoted at its lower end about a pivot pin 38, secured in the right side frame member 33 in axial alignment with the shaft 7.

Two pairs of electromagnets are provided at the opposite ends of the apparatus to effect rotation of the U- shaped member about its pivot points as defined, for instance, by pivot pin 38. More specifically, a first electromagnet 39, is provided at the front of the channel member 36 at the right side of the machine and a second electromagnet 41 of this pair is provided at the rear of the channel member 36. At the left side of the machine, an electromagnet 42 is provided in front of the channel member 36 and an electromagnet 43 is provided behind channel member 36. The electromagnets 39 and 42 are normally energized to retain the channel member 36 in the position illustrated in FIGURE 2. Upon enengization of the electromagnets 41 and 4-3 and de-energization of the electromagnets 39 and 42, the channel member 36 is moved to the rear of the apparatus, in referring to FIGURE 2, to the right of the apparatus illustrated therein. The forward movement of the channel member 36 causes the shaft 6, to pivot about the axis of the shaft 7, the shaft 7 of course pivoting therewith. Consequently, the type font 2 is moved to the right as illustrated in FIGURE 2, and presses the ribbon 4, against the paper disposed about the platen 3 to print the selected character. After the printing 'has been effected, the electromagnets 41 and 43 are de-energized and the electromagnets 39 and 42 are re-energized to return the type font 2 to a substantially vertical position out of engagement with the ribbon 4, and the paper disposed about the platen 3.

It will be noted that the teeth of the rack gears 12 and 13 become partially disengaged from the sector gears 17 and 18 during the printing operation. However, due to the friction between the shaft 6 on the one hand, the font 2 and the frame'members 14 and 16 on the other hand, the distance of travel of the font to effect printing which is only .020 of an inch, and the velocity at which the apparatus is operated, the vertical position of the font does not change a noticeable amount. As for rotational movement of the font, permitted to some extent by pa-rtial disengagement of the pinion 9 from the teeth of rack gear 11, this effect is completely unnoticeable, due, among other things, to the mechanical advantage of the system. The pinion 9 only moves a distance of .005 of an inch away from the teeth of the rack 11, so that very little if any effect takes place.

The type font carrier 1, is stepped from left to right across the apparatus, as viewed in FIGURE 1, by means of an appropriately driven steel tape 44, which is secured to both of the end walls 5 and 10 of the type font car- Tier 1. The mechanism for incrementally stepping the tape 44, and subsequently effecting carriage return, that is, return of the carrier 1 from right to left, is conventional and is not therefore, discussed herein. Also, guides are provided for the ribbon 4, at opposite ends of the type font carrier -1, the guides being secured to the end walls 5 and 10. These guides, as well as the mechanisms for advancing the ribbon are also not illustrated as they are completely conventional. Completely conventional mechanisms may also be employed to rotate the platen 3 during carriage return or under the control of external signals at other times.

As previously indicated, the particular character to be printed is selected by selectively translating the rack 11 and rotating the shaft 19. The mechanisms for effecting the movements of members 11 and 19 are disposed in a character selection mechanism housing 46, at the right of the apparatus as viewed in FIGURE 1, the mechanism imparting selected translation to both of these members. The rack 11 is supported at numerous points along its length by slotted studs 47, the rack gear 11 having a plurality of slots 48 formed therein, which are of a sufficient length to permit the requisite translation of the rack gear 11 to affect complete rotation of the font 2 to any one of its 8 positions. Rotation of the shaft 19 is also effected by translation of the shaft, the translatory motion being converted to rotary motion by means of translating helices 49 and 51, supported on the left side frame 32 and the right side frame 33, respectively. The translating helices 49 and 51 are provided with internal helices, and the portions of the shaft which extend into these members 49 and 51 are provided with mating external helices. Therefore, when the shaft 19 is translated along its longitudinal axis, the cooperating internal and external helices impart rotation to the shaft 19, the amount of rotation being a function of the distance through which the shaft 19 is translated. Thus, the font 2 is positioned both longitudinally and circumferentially as a result of translation of its two control members through selectable distances.

A translating control mechanism for the rack gear 11, may be directly coupled thereto, while the translating mechanism for the shaft 19 must be coupled thereto by a preloaded thrust bearing pair which maintain accurate positioning between the shaft and its driving member, and which permit relative rotation therebetween. Such a coupling is conventional and is not illustrated.

Since both the gear 11 and shaft 19 are positioned by translation, the mechanisms employed for driving the rack 11 and shaft 19 are translating mechanisms and they may be identical in construction. The selection mechanisms employed must, in the embodiment illustrated, each be capable of providing eight distinct positions of its output member so as to select the one of the eight bands of characters and one of the eight columns of the font 2. The mechanism must be capable of high-speed operation since, as previously indicated, it is an object of the invention to operate the apparatus of the present invention at approximately 100 characters per second. A mechanism which is suitable for use as the character selection mechanism of the present invention is described in US. Patent No. 3,089,413 of John H. MacNeill, James E. Bellinger and Thomas G. Holmes, and entitled Medium Speed Serial Printer. The apparatus described in the patent discloses a mechanical adder which operates on the binary notation so that 2 selections may be made. Where eight different selections are required as in the illustrated embodiment, a three-bit adder must be employed. Other mechanisms capable of high-speed operation and of providing the requisite number of distinct positions may be employed and coupled to the members 11 and 19 in the manner indicated above.

The selection mechanism contemplated to be employed and more specifically the selection mechanism of the aforesaid patent is a non-return-to-home type of apparatus; that is, after each selection, the head remains in its previously selected position until a command is received to proceed to a new selection. At this time, the head is translated and rotated if need be from the previously selected position to the new position. Internal logic in the character selection mechanism, which is provided by the mechanical arrangement of the aforesaid patent, remembers the old position so that when a new code is inserted the selection is made on the basis of the prior position. A complicating factor in the apparatus of the present invention arises from the fact that in order to maintain the weight of the moving parts at a minimum so as to maximize speed of operation, the control mechanisms for the font are stationary while the font moves. Permanent coupling must be provided between the font and its controls and in consequence each time the type font carrier 1 is stepped one position to the left during printing, the type font 2 is rotated due to the continued engagement of the pinion 9 with the rack 11. In order to simplify the resulting problems, the gearing is designed such that the font 2 is rotated one column (45) for each step of the carrier 1.

As indicated above the character selection mechanism remembers the last position to which it moved the type font 2, which position is actually incorrect due to subsequent rotation of the font 2 through one column. In order to overcome this problem, a binary number of from 0 to 7 is added to the code for selecting the column to be printed, the number added indicates the position of the type font carrier 1 relative to the initial printing column on the particular page under consideration. Thus, if one is printing in the home or lefthandmost print area of a page, zero is added to the incoming selection code. When the apparatus is stepped one position to the right, a one is added to the next incoming code. Two is added to the next incoming code to indicate that one is now printing in the third column or print area of the paper. The font 2 completes a cycle of rotation when it is stepped to the eighth typing area or multiples thereof, so that the type font 2 has been returned to its original or home position and the count added to the next incoming code should be Zero. The apparatus for compensating for the rotation of the type font from its home position as the head 1 is stepped across the paper may comprise a three stage binary counter. The count in the counter is added in a conventional binary number adder to the incoming three-bit selection code to affect compensation.

The circuitry for accomplishing the described result is illustrated in FIGURE 4 of the accompanying drawings in block diagram form. A three-stage binary counter 56 is adapted to receive a pulse over a lead 57 for each printing cycle of the apparatus. The count accumulated in the counter 56 is applied, in parallel, to a binary adder 58 which also receives the incoming code over three parallel input leads 59. Thus, the number stored in the adder 58 at any time represents the sum of the incoming binary code plus the count indicative of the column in which the printing is to occur relative to the lefthandmost character receiving area on the paper. The code developed in the adder 58 is extracted over parallel lead 61 each of which is connected to a different electromagnet for controlling the translatory motion of the output shaft of the character selection mechanism as indicated in the aforesaid patent. The count signal may be derived in a conventional manner from the same electrical circuitry which produces stepping of the type font carrier 1 above the print magnet circuits.- The counter must also be provided with a reset control so that when a carriage-return is effected from any position of the type font carrier 1, the counter is returned to a zero count. The reset pulse is applied to the counter in completely conventional manner via a reset lead 62, the voltage pulse developed on the reset lead 62 being derived from the same electrical circuit which initiates operation of the carriage return.

The electrical signals for controlling the apparatus of the invention; for instance, for controlling carriage return, the print magnets, the code magnets, etc. may be derived from any suitable source such as a punched tape or card reader, a computer, a communications link, etc. There is an upper limit on the rate at which information may be received but obviously no lower limit except that it would appear to be uneconomical to employ an equipment at speeds at which a less expensive equipment may be employed.

In the apparatus as previously described, the printing operation is effected by the print magnets operating on the U-shaped channel-member 36. In an alternative embodiment of the present invention which is illustrated in FIGURE 5, the mechanical advantage inherent in the lever mechanism provided by the shaft 6 and the pivot shaft 7 may be employed to reduce the driving stroke required to effect printing. The font 2 is stroked through 0.02 inch to effect printing and due to the ratio of the lever mechanism only .005 inch driving stroke is required if it is applied in the region of the pinion 9. This may be effected by permitting side play in the rack 11 on the pin 47. More particularly, the slots 48 formed in the rack gear are made slightly larger than the portions of the pins 47 which extend through the slots. This permits transverse movement of the rack gear; that is, as viewed in FIGURE 5, movement of the rack gear toward the left. This movement may be effected by a series of cam 66 spaced along a constantly driven shaft 67 supported between the end frame members 32 and 33.

The housing 1 is provided internally with an inwardly directed shoulder or shelf 68 having a downwardly extending spring-biased pin 69, engaging a flat formed on the shaft 7 adjacent the shaft 6. The spring biased pin 69 maintains the pinion rotated into engagement with the rack gear 11 and presses the rack gear back against the base circle of the cam 66. The shaft 67 is timed to present a lobe 71 to the back of the rack gear 11 at the proper time for printing, this causing the rack gear to move to the left as viewed in FIGURE 5, pivot the shaft 6 with its shaft 7 and cause the type font to engage the ribbon 4- and the paper. The lobes 71 may be spaced along the shaft 67 so that the printing force is applied at several distinct locations along the back of the rack gear 11. Three or four such lobes may be employed.

In order to reduce the rate of rotation of the shaft 67 several cams 66 may be disposed about the shaft so that successive cams produce successive printing cycles which are accurately timed by the rate of rotation of the shaft 67. Another advantage to this type of printing drive over and above that provided by the drive structure of FIGURE 1 is that a squeeze-type printing motion may be employed rather than a flow type printing motion. By properly contouring the earns 66, the particular character to be printed on the type font 2 is pressed into engagement with the paper thereby tending to produce a crushing motion and then the font is withdrawn at a controlled rate. This increases the life of the individual characters formed on the type font 2 and also makes for cleaner impressions on the paper. This type of printing operation also increases the life of the ribbon 4.

The high speed operation of the present invention is to a certain extent, of course, a function of the speed of the positioning mechanisms located in the box 46. If the mechanisms of the aforesaid patent are employed, character selection speeds of greater than one hundred characters per second may be achieved. More important, however, to the present invention are the mechanisms employed to effect the conversion of what must be considered a essentially a strip printer to a page printer without an appreciable loss of speed. In the present invention this conversion is effected by separating the type font from the selection mechanism, whatever form it might take, and providing appropriate interconnections therebetween which require a minimum of light-weight parts to be transported with the font. Further, the font serves as its own printing hammer but the mechanism for effecting this operation is also stationary and is not transported with the font. In consequence of the aforesaid arrangements, the weight of the mechanism which must be incrementally stepped across the printer is quite low and no problem is encountered in effecting the stepping at the desired rate.

The gearing mechanism for coupling the stationary character selection mechanism to the font also provides no problem ince all of the force necessary to drive these gearing mechanisms is readily available particularly if the selection mechanism of the aforesaid patent is employed. The rack and pinion arrangement is no problem and since the shaft 19 has a torque applied to both ends thereof, even though it is driven only at one end, it may be comparatively small without permitting unacceptable twisting in its center.

In order to synchronize the apparatus of the present invention with the character selection mechanism of the aforesaid patent, a common drive motor may be employed for all mechanisms, suitable gearing being employed to provide proper interrelationship between the speeds of the various units. For instance, energization of the magnets 39, 41, 42, 43 of FIGURES 1-3 or rate and phase of rotation of the shaft 67 of FIGURE 5 must be timed such that printing occurs at the same rate as character selection and only after each selection has been completed. Also, carrier advance must occur only after printing has occurred. All such synchronization, however, may be accomplished by completely conventional techniques and a basic rate is established by the main power souce, i.e. electric motor.

While we have described and illustrated several specific embodiments of our invention, it will be clear that variations of the details of construction which are specifically illustrated and described may be resorted to without departing from the true spirit and scope of the invention as defined in the appended claims.

We claim:

1. A type font mechanism comprising a hollow, cylindrical type font having a plurality of indicia arranged in rows and columns thereon, a splined shaft, said type font being positioned on said shaft for longitudinal movement thereon, said type font having internal splines engaging the splines of said splined shaft so that said type font rotates with said shaft, means for rotating said splined shaft to effect selection of a column of indicia, a pair of elongated members positioned on opposite sides of said type font generally parallel to its longitudinal axis, means interconnecting said members with said type font so that said members and said type front move as a unit longitudinally of said shaft, means for moving said elongated members to effect selection of a row of said indicia on said font, a type font carriage, said means for moving being mounted on said type font carriage for movement therewith, and means for mounting said splined shaft in said type font carriage for movement therewith and for rotation about an axis perpendicular to the axis of said splined shaft and parallel to a plane including said elongated members.

2. A type font mechanism comprising a hollow, cylindrical type font having a plurality of indicia arranged in rows and columns thereon, a splined shaft, said type font being positioned on said shaft for longitudinal movement thereon, said type font having internal splines engaging the splines of said splined shaft so that said type font r0- tates with said shaft, means for rotating said splined shaft to effect selection of a column of indicia, a hollow, rectangular member comprising two side members and two end members, said side members disposed on opposite sides of said type font parallel to the longitudinal axis thereof, said end members extending across opposite ends of said type font, said splined shaft extending through said end members and being rotatable relative thereto, said type font being constrained to move axially of said shaft with said end members, means for moving said side members to effect selection of a row of said indicia on said font, a type font carriage, and means for mounting said splined shaft in said type font carriage for movement therewith and for rotation about an axis perpendicular to the axis of said splined shaft and parallel to a plane including said side members.

3. A type font mechanism comprising a hollow, cylindrical type font having a plurality of indicia arranged in rows and columns thereon, a splined shaft, said type font being positioned on said shaft for longitudinal movement thereon, said type font having internal splines engaging the splines of said splined shaft so that said type font rotates with said shaft, means for rotating said splined shaft to effect selection of a column of indicia, a hollow, rectangular member comprising two sides members and two end members, said side members disposed on opposite sides of said type font parallel to the longitudinal axis thereof, said end members extending across opposite ends of said type font, said splined shaft extending through said end members and being rotatable relative thereto, said type font being constrained to move axially of said shaft with said end members, one surface of at least one of said side members having gear teeth formed thereon, a gear adapted to engage said gear teeth formed on said side member, means for rotating said gear to produce movement of said type font longitudinally of said splined shaft to effect selection of a row of said indicia on said font, a type font carriage, and means for mounting said splined shaft in said type font carriage for rotation about an axis perpendicular to the axis of said splined shaft and parallel to a plane including said side members.

4. A type font mechanism comprising a hollow, cylindrical type font having a plurality of indicia arranged in rows and columns thereon, a splined shaft, said type font being p itioned on said shaft for longitudinal movement thereon, said type font having internal splines engaging the splines of said splined shaft so that said type font rotates with said shaft, means for rotating said splined shaft to effect selection of a column of indicia, a hollow, rectangular member comprising two side members and two end members, said side members disposed on opposite sides of said type font parallel to the longitudinal axis thereof, said end members extending across opposite ends of said type font, said splined shaft extending through said end members and being rotatable relative thereto, said type font being constrained to move axially of said shaft with said end members, gear teeth being formed on a longitudinally extending edge of both said side members, a pair of gears each engaging gear teeth formed on a different one of said edges, means for rotating said pair of gears to produce movement of said type font longitudinally of said splined shaft to effect selection of a row of said indicia on said type font, a type font carriage, means for mounting said splined shaft on said type font carriage for rotation about an axis perpendicular to the axis of said splined shaft and parallel to a plane including said edges of said side members, means for moving said type font carriage parallel to the axis of rotation provided by said means for mounting said splined shaft on said type font carriage and means for moving said pair of gears with said type font carriage.

5. The combination according to claim 4 wherein said means for rotating said pair of gears comprises a second splined shaft, a slide member translatable along said second splined shaft and rotatable therewith, said pair of gears being mounted on said slide member for translation and rotation therewith, and wherein said type font carriage engages said slide member to cause said slide member to move with said type font carriage.

6. A type font mechanism comprising a type font carriage, a shaft mounted on said carriage for movement therewith and for rotation about its longitudinal axis and for rotation about an axis perpendicular to said longitudinal axis, a hollow type font mounted on said shaft for translation therealong and for rotation therewith about both said axes, said type font having a plurality of indicia arranged in rows and columns, means mounted for movement with said type font carriage for rotating said shaft about its said longitudinal axis for selecting a column of indicia, and means mounted for movement with said type font carriage for translating said type font parallel to said longitudinal axis of said shaft for selecting a row of indicia on said type font, said means for translating comprising a hollow frame and a rotatable gear, said frame being disposed about and engaging said type font means and constraining said frame to move parallel to said longitudinal aXis of said shaft, a rack gear formed on said frame, said rotatable gear engaging said gear on said frame to move said frame, a shaft extending over the length of movement of said type font carriage, said rotatable gear being mounted on said shaft for rotation therewith whereby rotation of said shaft translates said frame.

7. A printing mechanism comprising a shaft, a type font positioned on said shaft for rotation therewith and translation parallel to the longitudinal axis of said shaft, a first gear for rotating said shaft about said longitudinal axis, a second gear, means responsive to rotation of said second gear for translating said font, an elongated shaft, one of said gears being slidable on and rotatable with said elongated shaft, means for translating said elongated shaft and means for converting translation of said elongated shaft into rotation thereof.

8. A type font mechanism comprising a hollow type font having a plurality of indicia arranged in rows and columns thereon, an elongated shaft, said type font being positioned on said shaft for longitudinal movement thereon and rotation therewith, means for rotating said elon longitudinal axis of said type font, said end members extending across opposite ends of said type font, said elongated shaft extending through said end members and being rotatable relative thereto, said type font being constrained to move axially of said shaft with said end members, one surface of said side member having gear teeth formed thereon, a gear adapted to engage said gear teeth formed on said side member, means for rotating said gear to produce movement of said type font longitudinally of said elongated shaft to effect selection of a row of said indicia on said type font, a type font carriage, means for mounting said elongated shaft in said type font carriage for movement therewith and rotation about an axis perpendicular to the axis of said elongated shaft and parallel to a plane including said elongated members.

9. The combination according to claim 8 wherein said means for rotating said elongated shaft comprises a first gear secured to said elongated shaft, a further gear rotatably mounted on said type font carriage, said further gear being disposed on a side of said elongated shaft opposite to the direction of movement of said first gear upon initiation of rotation of said splined shaft about said lastmentioned axis.

References Cited by the Examiner UNITED STATES PATENTS 446,394 2/1891 Seifried 197-49 457,333 8/1891 Blickensderfer 197-55 477,224 6/ 1892 Pratt 197-49 1,983,099 12/1934 Sampson 197-49 2,127,251 8/1938 Fischer 197-12 2,757,775 8/1956 Hickerson 197-49 2,949,846 8/1960 Hoffman et a1 101-93 3,085,670 4/1963 Paige 197-50 X 3,089,413 5/1963 MacNeill et a1 101-93 3,157,115 11/1964 West et al 197-49 X 3,168,182 2/1965 Bernard et al 197-18 X 3,201,514 8/1965 Kleinschmidt et al.

ROBERT E. PULFREY, Primary Examiner. E. S. BURR, Assistant Examiner. 

1. A TYPE FRONT MECHANISM COMPRISING A HOLLOW, CYLINDRICAL TYPE FONT HAVING A PLURALITY OF INDICIA ARRANGED IN ROWS AND COLUMNS THEREON, A SPLINED SHAFT, SAID TYPE FONT BEING POSITIONED ON SAID SHAFT FOR LONGITUDINAL MOVEMENT THEREON, SAID TYPE FONT HAVING INTERNAL SPLINES ENGAGING THE SPLINES OF SAID SPLINED SHAFT SO THAT SAID TYPE FONT ROTATES WITH SAID SHAFT, MEANS FOR ROTATING SAID SPLINED SHAFT TO EFFECT SELECTION OF A COLUMN OF INDICIA, A PAIR OF ELONGATED MEMBERS POSITIONED ON OPPOSITE SIDES OF SAID TYPE FONT GENERALLY PARALLEL TO ITS LONGITUDINAL AXIS, MEANS INTERCONNECTING SAID MEMBERS WITH SAID TYPE FONT SO THAT SAID MEMBERS AND SAID TYPE FRONT MOVE AS A UNIT LONGITUDINALLY OF SAID SHAFT, MEANS FOR MOVING SAID ELONGATED MEMBERS TO EFFECT SELECTION OF A ROW OF SAID INDICIA ON SAID FONT, A TYPE FONT CARRIAGE, SAID MEANS FOR MOVING BEING MOUNTED ON SAID TYPE FONT CARRIAGE FOR MOVEMENT THEREWITH, AND MEANS FOR MOUNTING SAID SPLINED SHAFT IN SAID TYPE FONT CARRIAGE FOR MOVEMENT THEREIN AND FOR ROTATION ABOUT AN AXIS PERPENDICULAR TO THE AXIS OF SAID SPLINED SHAFT AND PARALLEL TO A PLANE INCLUDING SAID ELONGATED MEMBERS. 